Hulsius is best known for his translations of early travelers’ accounts, but he wrote two books that combine the study of coins with the biographies of emperors and historic persons: XIII Primorum Caesarum et LXIIII ipsorum uxorum effigies (1597) and Impp. Romanorum numismatum series a Julio Caesare ad Rudolphum II (1603).

This latter title was especially ambitious, providing brief biographies of Roman emperors, Byzantine emperors, and an assortment of western rulers through Rudolph II. It includes 150 engravings of coin portraits and commentary on the coin types and their relative scarcity.